1. Field of the Invention
This invention relates to an electric power supply apparatus using a flywheel generator for supplying electric power, for example, a nuclear fusion test device, an iron and steel manufacturing system or an electrical power source for a train or the like.
2. Description of the Prior Art
FIG. 1 shows conventional type of electrical power supply apparatus having, as its load, a toroidal magnetic field coil of a nuclear fusion test device as described in IEEE Transactions Energy Conversion. In this figure, 1 designates a toroidal magnetic filed coil; 2 designates an electric power converter having an input end connected to an utility line; 3 designates flywheel generator; 4 designates an electric power converter having an input end connected to the flywheel generator 3, the electric power converter 4 being connected in series with the power converter 2 and used as a converter; 5A and 5B designate a transformer connected to a system bus line; 6 designates an electric power converter having an input end connected to the transformer 5B and used as a converter; 7 designates a DC reactor having one end connected to the power converter 6; 8 designates a power converter used as an inverter for converting DC power supplied from the DC reactor 7 into an AC power; 9 designates an AC reactor mounted between the flywheel generator 3 and the power converter 8; 10 designates a transformer arranged between the flywheel generator 3 and the power converter 4; and 14, 14A and 14B designate a breaker, respectively.
A thyristor driving device is composed of the above-mentioned power converters 6 and 8, the DC reactor 7 and the AC reactor 9.
Operation of this conventional system will now be described.
If electric power is to be supplied to the toroidal magnetic field coil 1, which acts as a load, AC electric power is converted into DC electric power through both the power converter 2, which is connected to the utility line, and the power converter 4, which is connected to the flywheel generator 3. This DC electric power is then supplied to the toroidal magnetic field coil 1.
Alternatively, if electric power is used to accelerate the flywheel generator 3, AC electric power from the utility line is supplied to the electric power converter 6 through the transformer 5B and converter into DC electric power there. This DC electric power is then supplied to the electric power converter 8 through DC reactor 7. This electric power converter 8 is used as an inverter wherein the DC electric power is converted into AC electric power again. This AC electric power is then supplied to the flywheel generator 3 through the AC reactor 9.
As a result, the flywheel generator 3 is accelerated by the supplied electric power so as to accumulate mechanical energy, which may later be supplied to the toroidal magnetic field coil 1 as electrical energy.
In the foregoing description, the toroidal magnetic field coil 1 is connected in series between the power converter 2, which receives electric power from the utility line, and the power converter 4, which receives electric power from the flywheel generator 3. The system; may also be arranged so that the utility line is eliminated and only the power supplied from the flywheel generator 3 is applied to the load.
In the foregoing description, the toroidal magnetic field coil 1 of a nuclear fusion test equipment is used as the load. This is only one example, however. Other examples of the load include an electric motor, such as one used in an iron and steel manufacturing plant, and an electric train, such as one in an electric railway system and the like. Furthermore, as described above, the system is constituted such that energy is temporarily stored in the flywheel generator 3 and this stored energy is supplied to the load as required. A different type of system may alternatively be used with the invention.
A disadvantage associated with the conventional type of the electric power supply apparatus described above is that it requires several electric power converters; the power converters 2 and 4 for supplying electric power to the load and the electric power converters 6 and 8 for supplying electric power to the flywheel generator 3.